Means for feeding fuel to furnaces



A. G. FUX. MEANS FOR FEEDING FUEL TO-FURNACES.

APPLICATION FILED JULY 26, I917.

Patented 25, 1921,

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UNITED STATES PATENT oFFIcE.

ALFRED GEORGE FOX, OF NEW CROSS, ENGLAND.

MEANS FOR FEEDING FUEL TO FURNACES.

Application filed July 2 Relating .to Means for Feeding Fuel toFurnaces, of which the following is a specification.

This invention relates to means for feeding fuel to furnaces of the typein which the fuel is fed from the front to the rear of the grate by themovement of the grate itself. These grates are usually'supplied withfuel by gravity through a conical hopper and the thickness of the layerof fuel passing on to the grate is regulated by means of a guillotinetype of door which is adjustable in a vertical direction. In order toconsume fuel efficiently it is essential that the whole of the gratearea from the front to the (lumping bars be kept uniformly covered andwe have found that with many classes of fuel the rate of burning atdifferent areas across the grate varies considerably, owing probably tovariations in the draft, or in the brick-work radiation or to othercauses. The result of this is that although a uniform layer of fuel maybe led on to the grate through the guillotine door, combustion at somepoints is completed much sooner than at other points so that before thegrate reaches the dumping bars some parts of it may be bare of fuelwhile atother points the fuel is incompletely burned and falls into theash hopper in this state. We have also found that both the rate ofcombustion and the areas over which the varying combustion takes placemay vary considerably with differentclasses of fuel. Whatever thecauseof the varying rate of combustion, it is Very ruulesirable, as theefficiency of the boiler may be lowered very considerably thereby.

fine object of this invention is to overcome this objection and to thisend it com sists in providing a door, the lower or strickling portion ofwhich is divided into a number of easily, relatively adjustable sectionsso that by raising and lowering these sections the thickness of thelayer of fuel led on to the grate may be varied at different points. l

In carrying this invention into effect according to one modification, weprovlde in front of the furnace across girder from which all thesections of the door with their Specification of Letters Patent.

cal furnace front or lintel.

Patented Jan. 25, 1921.

1917. Serial No. 182,865.

adjusting apparatus are suppoited. The ad usting mechanism may consistof a screw and nut, rack and pinion or any other suitable device Thecross girder may also be provlded with adjusting means so that the wholeof the sections may be adjusted simultaneously before or after beingadjusted individually. The individual sections of the door may be of anysuitable shape but We prefer to make them substantially rectangular andhollow for a portion of their length, the interior space being filledwith some heat insulating material so as to prevent radiation from thefurnace through the door to the unburned fuel in the hopper. It.

is also desirable to provide the lower ends witheasily renewable pointsso that should the lower ends become burned or otherwise destroyed theycan be renewed. This is a great advantage over the bresent guillotinetype of door as in case of burning the whole door has often to berebuilt and renewed whereas with the present invention only the sectionswhich are damaged require to be renewed'or fitted with new end pieces,which can readily be done without putting the boiler out of action.

The existing types of-door usually consist of brick inclosed in a metalframing, and the inside face, which is next to the fire, travels up anddown in proximity to the fixed verti- As in everyday use considerabledistortion, and displacement of bricks usually takes place in thefurnace door, the necessary clearance between these faces to preventjamming is often such that considerable air leakage takes place into thefurnace,the result often seriously lowering the temperature of thecombustion arch.

A further object of our invention is to construct a sectionalized doorso that it overcomes this disadvantage also, and consists in providingthe upper part of the door with lean-to sections which normally makerubbing contact with the vertical furnace front or lintel. Thesesections may be separate and independent of the sections which controlthe thickness of the layer of fuel and supported from the cross girderor they may be integral therewith; in either case, for the purpose ofsealing, the sections may be provided with substantially horizontalprojections or noses which are held by gravity against the lintel.

As the sections are independent of each through contact with the burninother each of these projections will make rubbing contact with thelintel plate so that an effective air seal isobtained. The accompanyingdrawings will serve to illustrate our invention, .igure 1 being a frontelevation partly in section of a furnace door Fig. 2 a sectional sideelevation on line 2- 2, of Fig. 1.

in the drawings, a represents a cross girder forming part of the frameof the door adapted to be raised and lowered by any suitable mechanism,as pulleys 1, cable 2, and counterweight 8. The door consists of anumber of separate sections Z) which are secured to the cross girder aby means of bolts 0 which pass through bosses formed on the girder andare provided with nuts 0 at their upper ends so arranged that as thenuts are rotated the section to which its bolt is attached will beraised or lowered Thi allows or" the thickness of the layer of fueladmitted under any section being regulated to the desired thickness andafter each of the sections has been adjusted the thickness of the layerpassing on to the grate under all the sections can be variedsimultaneously by the same amount by raising or lowering the crossgirder through suitablemechanisni,

such as the pulley and weight arrangement shown in 1. The individualsectionsoi": the door each consists ota main portion of substantiallyrectangular shape the interior of which is filled. with some heatresisting material to prevent radiation from the fun nace through thedoor to the unburned fuel in the hopper 9. As the lower ends of guilotine doors are subjected to eat he coal t. rapidly become burned orotherwise ('1. stroyed in places and one of the main advantages ofmaking the door in sections is that one or more sections can be removedand renewedwithout having to replace the whole door. To still furtherimprove the construction we provide each section with renewablenose-piece 7t clamped to the lower end'by means of a c bolt l: andcontaining heat insulating material such lire brick m which may be heldin place by means of dowel pins a cast on'the main portion 6 of thesection. arranged that the fire brick is not only firmly clamped thelower end of the main portion, but the bolt 1: being located on theoutside of the furnace door it is .tully protected from the deleteriousaction of the heat from the furnace. The sections pivoted. to theiradjusting bolts by pivots or pins 5 which'lie in avertical plane passingoetween the lintel and the center of gravity of every section. Theprojecting heads 0 of the The bolt 7': is so meagre jections 0 on theindividual sections will accommodate themselves to the lintel andcontinue to be held in close contact with it and prevent alr fromleaking into the furnace.

fit the same time amming or stilt working of the door is avoided.

Guides extending from the cross girder are provided for each section asindicated at 6, Fig. 1 to prevent any undue move ment.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. The combination with a'furnace of a door therefor composed of anumber of separate sections, a girder from Which'said sections aresupported, means for adjusting each section independently with respectto the girder and means for adjusting the girder with respect to thefurnace.

2. In combination, a furnace, a plate or lintel forming part of theframe thereof, a

door comprising a girder and a plurality of separate sections, pivotmeans fastening each of said sections to said girder, each of said pivotmeans lying in a-ve'rtical plane between the lintel and the center ofgravity of its section, the sections bein individually held by gravityin contact wit 1 the lintel to form a seal therewith.

The combination with a furnace of a door therefor comprising a number ofsepa- 1" .e individually adjustable sections, a

.girder from which'said sections are suspended, a projection secured tothe rear side oi": each of the sections, a plate or lintel forming partof the framework of the fur.

nace, pivot means securing each of the sections to the girder, each ofsaid pivot means lyingin a vertical plane between the lintel and thecenter of grat ity of its section, said projections being held bygravity in contact with the lintel to form a seal therewith.

l. In combination, a furnace, a fuel feeding device therefor, a dooradjustable as whole to regulate the feed thereof, comprising a' crossgirder and a plurality of separate sections supported by saidgirder,said girder having guides for said sections, and means carried by thegirder for adjusting the sections independently.

In witness whereof, I have hereunto set my hand this 6th day of July1917.

ALFRED ononon FOX.

Witnesses J OHN GRAY, CHARLES H. Bonenss.

